Network failure protection method, system, and storage medium

Abstract

A method, a system and a storage medium for network failure protection belonging to the field of network technologies. The method comprises: allocating, for each forwarding link of the ring topology, a protection ring bit position opposite to the direction of a working path; newly adding BRFT for storing adjacent forwarding table entries related to forwarding along the direction of the protection ring bit position; and when a BIER message is forwarded along the working path, if a BFR detects that the downstream adjacency fails, searching for entry content of the BTAFT, finding the correlation between the link bit position of the fault forwarding link and the protection ring bit position, and forwarding, on the basis of entry content of the BRFT, the BIER message to the opposite end fault point of the opposite end along the direction of the protection ring bit position.

The invention claimed is: 
     
       1. A network failure protection method, comprising:
 allocating a protection ring bit position for each forwarding link of a ring topology, wherein a direction of the protection ring bit position is opposite to a working path of a corresponding forwarding link; 
 newly adding a Bit Index Explicit Replication (BIER) Ring Forwarding Table (BRFT), wherein the BRFT is configured to store an adjacent forwarding table entry related to forwarding along the direction of the protection ring bit position; and 
 when a BIER message is forwarded along the working path, in response to a failure of downstream adjacency of a forwarding link detected by a BIER Forwarding Router (BFR), searching for entry content of a Bit Index Explicit Replication Traffic Engineering (BIER-TE) Adjacency FRR Table (BTAFT) to find a correlation between a link bit position of a failure forwarding link and the protection ring bit position, and forwarding, on the basis of the entry content of the BRFT, the BIER message to a failure point of an opposite end along the direction of the protection ring bit position. 
 
     
     
       2. The network failure protection method according to  claim 1 , wherein the BRFT includes Bit Index Information, Adjacencies Information, DNR (Do Not Reset) Information, C-BM (Clear-BitMask) Information that needs to be cleared when a message is forwarded and Entry Status Information. 
     
     
       3. The network failure protection method according to  claim 1 , wherein before when the BIER message is forwarded along the working path, in response to the failure of downstream adjacency of the forwarding link detected by the BFR, searching for entry contents of the BTAFT to find the correlation between the link bit position of the failure forwarding link and the protection ring bit position, and forwarding, on the basis of the entry content of the BRFT, the BIER message to the failure point of the opposite end along the direction of the protection ring bit position, the method further comprises:
 expanding a BIER message header, to distinguish, by a newly added field, whether the BIER message is forwarded along the working path or along the direction of the protection ring bit position. 
 
     
     
       4. The network failure protection method according to  claim 3 , wherein when the BIER message is forwarded along the working path, in response to the failure of downstream adjacency of the forwarding link detected by the BFR, searching for entry contents of the BTAFT to find the correlation between the link bit position of the failure forwarding link and the protection ring bit position, and forwarding, on the basis of the entry content of the BRFT, the BIER message to the failure point of the opposite end along the direction of the protection ring bit position, comprises:
 in response to a failure of the downstream adjacency to which the BIER message needs to be forwarded, modifying a bit string content of the BIER message to replace the link bit position of the failure forwarding link with the protection ring bit position of the failure forwarding link, and setting the newly added field of the BIER message header. 
 
     
     
       5. The network failure protection method according to  claim 4 , wherein, when the BIER message is forwarded, whether to search an original Bit Index Forwarding Table (BIFT) or to search the newly added BRFT to forward is determined according to whether the newly added field of the BIER message head is set. 
     
     
       6. The network failure protection method according to  claim 5 , wherein, searching the BRFT to forward comprises:
 copying and forwarding bit-by-bit according to a bit string at the BIER message header, and checking table entries of the BRFT one by one to detect whether a current table entry of the BRFT meets a condition of off-protection ring; and 
 responsive to determining that the condition of off-protection ring is met, clearing a setting of the newly added field at the BIER message header, copying the BIER message, and searching the BIFT to forward; or 
 responsive to determining that the condition of off-protection ring is not met, directly copying the BIER message and forwarding the BIER message through an adjacent port corresponding to the current table entry of the BRFT. 
 
     
     
       7. The network failure protection method according to  claim 1 , wherein the entry content of the BRFT is formed by, according to a distribution process of the protection ring bit position, carrying out BRFT table configuration on each node passed by the protection ring bit position. 
     
     
       8. The network failure protection method according to  claim 7 , wherein before when the BIER message is forwarded along the working path, in response to the failure of downstream adjacency of the forwarding link detected by the BFR, searching for entry contents of the BTAFT to find the correlation between the link bit position of the failure forwarding link and the protection ring bit position, and forwarding, on the basis of the entry content of the BRFT, the BIER message to the failure point of the opposite end along the direction of the protection ring bit position, the method further comprises:
 sending the table entries related to BIER message forwarding to the BFR through a southbound interface. 
 
     
     
       9. A non-transitory storage medium, storing at least one program, wherein when executed by at least one processor, the at least one program implements the steps of the method of network failure protection according to  claim 1 . 
     
     
       10. A network failure protection system, comprising a Bit Index Explicit Replication Traffic Engineering (BIER-TE) controller and a Bit Index Explicit Replication (BIER) Forwarding Router, wherein:
 the BIER-TE controller is configured to allocate a protection ring bit position for each forwarding link of a ring topology, wherein a direction of the protection ring bit position is opposite to a working path of a corresponding forwarding link, newly add a BIER Ring Forwarding Table (BRFT), wherein the BRFT is configured to store an adjacent forwarding table entry related to forwarding along the direction of the protection ring bit position, and forward the table entry related to forwarding of a BIER message to the BIER Forwarding Router through a southbound interface; and 
 the BIER Forwarding Router is configured to receive the table entry related to forwarding of the BIER message sent from the BIER-TE controller through the southbound interface; when the BIER message is forwarded along the working path, in response to a failure of downstream adjacency of a forwarding link detected by the BIER forwarding router (BFR), search for the entry content of a BIER-TE Adjacency FRR Table (BTFT) to find a correlation between a link bit position of a failure forwarding link and the protection ring bit position, and forward, on the basis of the entry content of the BRFT, the BIER message to a failure point of an opposite end along the direction of the protection ring bit position. 
 
     
     
       11. The network failure protection system according to  claim 10 , wherein the BIER-TE controller comprises:
 a Path Computation Element (PCE), configured to calculate a protection ring path of each forwarding link to determine the protection ring bit position corresponding to the protection ring path; 
 a ring BitPosition (BP) resource allocator, configured to allocate the protection ring bit position for each forwarding link, and determine whether the protection ring bit position is able to be shared; 
 a BRFT entry generator/integrator, configured to generate an initial BRFT table according to the allocation of the protection ring bit position, and integrate Clear-BitMask (C-BM) information of the initial BRFT table according to a BRFT integration method; 
 a protection correlation manager, configured to manage the correlation between the link bit position of each forwarding link and the protection ring bit position; and 
 a table entry issuer, configured to issue the table entry related to forwarding of the BIER message to the BIER Forwarding Router through the southbound interface. 
 
     
     
       12. The network failure protection system according to  claim 10 , wherein the BIER Forwarding Router comprises:
 an entry configurator, configured to receive the table entry related to forwarding of the BIER message sent from the BIER-TE controller through the southbound interface; 
 a message encapsulator, configured to encapsulate the BIER message, wherein the encapsulation includes modifying a bit string content of the BIER message and setting for a newly added field in the BIER message header; 
 a message analyzer, configured to extra analyze whether or not the newly added field of the BIER message header is set; 
 a message sender/receiver, configured to send and receive the BIER message; 
 a BIER-TE protection forwarder, configured to determine, according to a setting condition of the newly added field in the BIER message header, whether the BIER message is forwarded along the working path or along the direction of the protection ring bit position; 
 a BRFT forwarder, configured to perform bit-wise copying and forwarding according to the newly added field in the BIER message header in combination with the entry contents of the BRFT; and 
 a fast detector, configured to perform a connectivity detection on each forwarding link in the ring topology by a fast detection means.